Copenhagen Countdown: 31 Days
Most of those concerned with climate have had their eyes on Barcelona this week, where delegates from 192 countries plus hundreds of observers, campaigners, lobbyists - and journalists - convened for the final session of preparatory talks before the UN climate summit in Copenhagen.
As I've reported, there's been a deal of tension between rich and poor - with the developing world accusing the developed world of forgetting about its needs, as rich nations refuse to cut greenhouse gas emissions enough to stave off "dangerous" climate change (their view).
How much of the rancour turns out to be real and how much synthesized as a political bargaining tool we will find out in Copenhagen - although perhaps not until the last few days of that meeting.
What's certain is that unless the US comes forward with a pledge on reducing its greenhouse gas emissions, there will be no deal of any kind, legally binding or politically binding (whatever those phrases may mean precisely).
If the US does produce a figure, it can realistically be in no other ballpark than a 17-20% reduction from 2005 levels by 2020 - that's roughly what President Obama pledged before the election, and roughly what the Boxer-Kerry bill now going through the Senate would produce.
In a news conference here, US negotiator Jonathan Pershing reckoned this would put the US way ahead of the EU on ambition - the US would cut emissions faster that Europe over the next 11 years.
The reason is that the EU has already cut emissions markedly between 1990 - the baseline that everyone else uses - and today.
And against that baseline, the US pledge will only be about 4% - paltry beside the EU's 20-30% and Japan's 25%.
Mr Pershing may not want the administration to which he belongs to shoulder the burden of making cuts that the Bush government did not... but from the perspective of a developing country many miles away, the US is the US is the US, whoever is in charge at various times.
Is there a formula that everyone could live with? Will the EU consider 4% "comparable" to its own efforts?
Would developing countries accept a US pledge as binding in the absence of Senate legislation - given that on the Kyoto Protocol, the US first signed, then declined to ratify, then withdrew?
Could money and technology bridge the gap?
Is it, indeed, bridgeable?
Mr Pershing said it's not yet been decided whether the US will put forward a target in Copenhagen and one reason for the non-decision - if non-decision it is, rather than a decision that's been taken and is being kept under wraps - is presumably the sticky passage envisaged for the Boxer-Kerry bill.
Republican senators on the influential Environment and Public Works Committee decided to boycott discussions on the bill this week, saying that a full analysis of its financial costs and benefits was needed first.
So committee chair - and bill sponsor - Barbara Boxer pushed it through the committee without debate - a procedure that's apparently rarely used.
However, in a sign that not everything is going swimmingly well, senators John Kerry, Joe Lieberman and Lindsey Graham started working on a "parallel track" towards a bill that can get the 60 votes necessary to pass legislation in the full Senate.
It's likely to include more support for nuclear power and perhaps for the oil and gas industry, while maintaining the cap-and-trade programme that is the current bill's centerpiece.
What this means for prospects of passing climate legislation isn't clear - perhaps not to anyone. But it doesn't exactly sound like a fast track - particularly as the further legislation evolves from the text that the House of Representatives passed in June, the harder it will be to reconcile the two.
A high-level European delegation was in Washington this week and although German Chancellor Angela Merkel's address to Congress asking for more action on climate change was received with applause on the Democrat side, there was reportedly silence on the other side of the house - another indication that not all US lawmakers are convinced that their president is on the right track on climate change.
Other potentially significant moves this week include the meeting of G20 finance ministers - a meeting expressly charged at the last G20 summit in Pittsburgh with putting a new offer of climate finance on the table.
Campaigners are urging them to phase out fossil fuel subsidies as soon as possible. To do so was a pledge made by governments at the G20 summit - it's also an agreed aim under the UN climate convention, which dates all the way back to 1992.
At the time of writing, the finance ministers' meeting is under way but nothing has yet emerged - you can follow my colleague Andrew Walker's reports on the BBC News website and we'll look at it again next week.
A conference will open in the Maldives next week of countries considered especially vulnerable to climate change. Governments invited include Bangladesh, Costa Rica, and a number of Caribbean and Pacific island states.
What they'll come up with is likely to include demands for reducing greenhouse gas emissions further and faster than is currently envisaged under the UN process.
The UN texts, the advice from the Intergovernmental Panel on Climate Change (IPCC) and some of the developed country targets are loosely aimed at keeping the rise in global average temperatures within 2C since pre-industrial times.
The equations are inexact but that may roughly translate to keeping greenhouse gas concentrations below the equivalent of 450 parts per million (ppm) of carbon dioxide.
For the small island developing states (SIDS), that's too much. They want a maximum of 350ppm adopted as the benchmark.
Although on the surface politicians - especially from Europe - are trimming expectations for Copenhagen, behind the scenes they are also encouraging campaigners to step up the pressure in the intervening weeks.
This week, we've had aliens wandering round asking "Where are the leaders?" and barrages of alarm clocks indicating the shortness of time before the summit... and we also have what are probably the first climate hunger strikers.
Anna Keenan and Sara Svensson have vowed to go without food until the Copenhagen summit at least - perhaps beyond, if there is no agreement that meets their satisfaction.
"We're undertaking the hunger strike because we're not seeing much action from governments and we really need it," she told me.
Can their action affect governments and persuade them to amend their positions in the four weeks between now and the start of the Copenhagen talks? Should it?
As always, if you think I've missed any significant developments this week or interesting ones coming up, please post a comment.